﻿using System;
using System.IO;
using System.Diagnostics;
using System.Threading;
using System.Collections.Generic;
//using IAP;
namespace Ymodem
{
    public enum InitialCrcValue { Zeros, NonZero1 = 0xffff, NonZero2 = 0x1D0F }

    public class Ymodem
    {

        /*
         * Upload file via Ymodem protocol to the device
         * ret: is the transfer succeeded? true is if yes
         */
        private string path;
        public string Path { get { return Path; } set { path = value; } }
        //private string portName;
        //public string PortName { get { return portName; } set { portName = value; } }
        //private int baudRate;
        //public int BaudRate { get { return baudRate; } set { baudRate = value; } }
        //private int dataBit;
        //public int DataBit { get { return dataBit; } set { dataBit = value; } }
        //private string stopBit;
        //public string StopBit { get { return stopBit; } set { stopBit = value; } }
        //private int parity;
        //public int Parity { get { return parity; } set { parity = value; } }
        private System.IO.Ports.SerialPort serialPort;
        public System.IO.Ports.SerialPort SerialPort { get { return serialPort; } set { serialPort = value; } }
        public event EventHandler NowDownloadProgressEvent;
        public event EventHandler DownloadResultEvent;

        public void YmodemUploadFile()
        {
            /* control signals */
            const byte SOH = 1;
            const byte STX = 2;  // Start of TeXt 
            const byte EOT = 4;  // End Of Transmission
            const byte ACK = 6;  // Positive ACknowledgement
            const byte NAK = 21; //下位机请求重新发送
            const byte C = 67;   // capital letter C

            /* sizes */
            const int headSize = 128;
            const int dataSize = 1024;
            const int crcSize = 2;

            /* THE PACKET: 1029 bytes */
            /* header: 3 bytes */
            // STX
            int packetNumber = 0;
            int invertedPacketNumber = 255;
            /* data: 1024 bytes */
            byte[] data128 = new byte[headSize];
            byte[] data1024 = new byte[dataSize];
            /* footer: 2 bytes */
            byte[] CRC = new byte[crcSize];

            /* get the file */
            FileStream fileStream = new FileStream(@path, FileMode.Open, FileAccess.Read);
            try
            {
                //serialPort.Write(new byte[] { 0x31 }, 0, 1);
                /* send the initial packet with filename and filesize */
#if true
                if (serialPort.ReadByte() != C)
                {
                    Debug.WriteLine("Can't begin the transfer.");
                    //serialPort.Close();
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
                else
                {
                    Debug.WriteLine(" begin the transfer.");

                }
#else
                if ((0 == sp_RecvList.Count) || (sp_RecvList[sp_RecvList.Count - 1] != C))
                {
                    Debug.WriteLine("Can't begin the transfer.");
                    serialPort.Close();
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
                else
                {
                    Debug.WriteLine(" begin the transfer.");
                    sp_RecvList.Clear();
                }

#endif
                serialPort.DiscardInBuffer();
                sendYmodemInitialPacket(SOH, packetNumber, invertedPacketNumber, data128, headSize, path, fileStream, CRC, crcSize);

#if true
                byte temp = (byte)(serialPort.ReadByte());
                Debug.WriteLine(temp);
                if (temp != ACK)//(serialPort.ReadByte() != ACK)
                {
                    Debug.WriteLine("Can't send the initial packet.");
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }

                if (serialPort.ReadByte() != C)
                {
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
#else
                Thread.Sleep(10);
                if ((0 == sp_RecvList.Count) || (sp_RecvList[sp_RecvList.Count - 2] != ACK))
                {
                    Debug.WriteLine("Can't send the initial packet.");
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
                if ((0 == sp_RecvList.Count) || (sp_RecvList[sp_RecvList.Count - 1] != C))
                {
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
                sp_RecvList.Clear ();

#endif
                /* send packets with a cycle until we send the last byte */
                int fileReadCount;
                do
                {
                    /* if this is the last packet fill the remaining bytes with 0 */
                    fileReadCount = fileStream.Read(data1024, 0, dataSize);
                    if (fileReadCount == 0) break;
                    if (fileReadCount != dataSize)
                        for (int i = fileReadCount; i < dataSize; i++)
                            data1024[i] = 0;

                    /* calculate packetNumber */
                    packetNumber++;
                    if (packetNumber > 255)
                        packetNumber -= 256;
                    Console.WriteLine(packetNumber);

                    /* calculate invertedPacketNumber */
                    invertedPacketNumber = 255 - packetNumber;

                    /* calculate CRC */
                    //Crc16Ccitt crc16Ccitt = new Crc16Ccitt(InitialCrcValue.Zeros);
                    //CRC = crc16Ccitt.ComputeChecksumBytes(data);
                    CRC = ComputeChecksumBytes(data1024, data1024.Length); 

                    /* send the packet */
                    sendYmodemPacket(STX, packetNumber, invertedPacketNumber, data1024, dataSize, CRC, crcSize);
                    int progress = (int)(((float)dataSize * packetNumber) / fileStream.Length * 100);
                    Debug.WriteLine("progress:  " + progress);
                    if (progress > 100) progress = 100;
                    NowDownloadProgressEvent.Invoke(progress, new EventArgs());

                    /* wait for ACK */
#if true
                    /*原来的代码*/
                    //temp = (byte)serialPort.ReadByte();
                    
                    //if (temp != ACK)
                    //{
                    //    Debug.WriteLine("temp" + temp);
                    //    Debug.WriteLine("Couldn't send a packet.");
                    //    DownloadResultEvent.Invoke(false, new EventArgs());
                    //    return;// false;
                    //}
                    /*支持重传处理*/
                    while (true)
                    {                        
                        temp = (byte)serialPort.ReadByte();
                        if (ACK == temp)//设备正确响应
                        {
                            break;
                        }
                        if (C == temp)//设备请求重传该包
                        {
                            sendYmodemPacket(STX, packetNumber, invertedPacketNumber, data1024, dataSize, CRC, crcSize);
                        }
                        else//错误，返回失败
                        {
                            Debug.WriteLine("temp" + temp);
                            Debug.WriteLine("Couldn't send a packet.");
                            DownloadResultEvent.Invoke(false, new EventArgs());
                            return;// false;
                        }
                    }
#else
                    Thread.Sleep(10);
                    if ((0 == sp_RecvList.Count) || (sp_RecvList[sp_RecvList.Count - 2] != ACK))
                    {
                        //Debug.WriteLine("temp" + temp);
                        Debug.WriteLine("Couldn't send a packet.");
                        DownloadResultEvent.Invoke(false, new EventArgs());
                        return;// false;
                    }
                    sp_RecvList.Clear();

#endif
                } while (dataSize == fileReadCount);

                /* send EOT (tell the downloader we are finished) */
                /*首次发送结束*/
                serialPort.Write(new byte[] { EOT }, 0, 1);
                if (NAK != (byte)serialPort.ReadByte())
                {
                    Debug.WriteLine("Can't complete the transfer.");
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
                /*再次发送结束*/
                serialPort.Write(new byte[] { EOT }, 0, 1);
                if (ACK != (byte)serialPort.ReadByte())
                {
                    Debug.WriteLine("Can't complete the transfer.");
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
                if (C != (byte)serialPort.ReadByte())
                {
                    Debug.WriteLine("Can't complete the transfer.");
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
                /* send closing packet */
                packetNumber = 0;
                invertedPacketNumber = 255;
                data128 = new byte[headSize];
                CRC = new byte[crcSize];
                sendYmodemClosingPacket(SOH, packetNumber, invertedPacketNumber, data128, headSize, CRC, crcSize);
                /* get ACK (downloader acknowledge the EOT) */
                if (serialPort.ReadByte() != ACK)
                {
                    Debug.WriteLine("Can't complete the transfer.");
                    DownloadResultEvent.Invoke(false, new EventArgs());
                    return;// false;
                }
            }
            catch (TimeoutException)
            {
                throw new Exception("Eductor does not answering");

            }
            finally
            {
                fileStream.Close();

            }
            //serialPort.Close();
            Debug.WriteLine("File transfer is succesful");
            DownloadResultEvent.Invoke(true, new EventArgs());
            return;// true;
        }

        private void sendYmodemInitialPacket(byte STX, int packetNumber, int invertedPacketNumber, byte[] data, int dataSize, string path, FileStream fileStream, byte[] CRC, int crcSize)
        {
            string fileName = System.IO.Path.GetFileName(path);
            string fileSize = fileStream.Length.ToString();
            Debug.WriteLine("fileSize" + fileSize);
            /* add filename to data */
            int i;
            for (i = 0; i < fileName.Length && (fileName.ToCharArray()[i] != 0); i++)
            {
                data[i] = (byte)fileName.ToCharArray()[i];
            }
            data[i] = 0;

            /* add filesize to data */
            int j;
            for (j = 0; j < fileSize.Length && (fileSize.ToCharArray()[j] != 0); j++)
            {
                data[(i + 1) + j] = (byte)fileSize.ToCharArray()[j];
            }
            data[(i + 1) + j] = 0;

            /*add realy time to data*/
            string dataTime_Str = DateTime.Now.ToString();
            char[] dataTime_Array = dataTime_Str.ToCharArray();
            int z;
            for (z = 0; z < dataTime_Str.Length-5; z++)
            {
                data[((i + 1) + j + 1) + z] = (byte)dataTime_Array[z+2];
            }

            /* fill the remaining data bytes with 0 */
            for (int k = (((i + 1) + j) + 1) + z; k < dataSize; k++)
            {
                data[k] = 0;
            }

            /* calculate CRC */
            CRC = ComputeChecksumBytes(data, data.Length);
            /* send the packet */
            sendYmodemPacket(STX, packetNumber, invertedPacketNumber, data, dataSize, CRC, crcSize);
        }

        private void sendYmodemClosingPacket(byte STX, int packetNumber, int invertedPacketNumber, byte[] data, int dataSize, byte[] CRC, int crcSize)
        {
            /* calculate CRC */
            CRC = ComputeChecksumBytes(data, data.Length);
            /* send the packet */
            sendYmodemPacket(STX, packetNumber, invertedPacketNumber, data, dataSize, CRC, crcSize);
        }

        private void sendYmodemPacket(byte STX, int packetNumber, int invertedPacketNumber, byte[] data, int dataSize, byte[] CRC, int crcSize)
        {
            serialPort.Write(new byte[] { STX }, 0, 1);
            serialPort.Write(new byte[] { (byte)packetNumber }, 0, 1);
            Debug.WriteLine("\rpacketNumber:" + packetNumber);
            serialPort.Write(new byte[] { (byte)invertedPacketNumber }, 0, 1);
            Debug.WriteLine("\rinvertedPacketNumber:" + invertedPacketNumber);
            serialPort.Write(data, 0, dataSize);
            serialPort.Write(CRC, 0, crcSize);
            Debug.WriteLine("\rdata:");
#if false
            for (UInt16 i = 0; i < dataSize; i++)
            {
                //Debug.Write(string.Format("{0:X}", data[i]) + ",");
                Debug.Write(data[i] + ",");
            }
            Debug.WriteLine("");
            Debug.Write(string.Format("{0:X}", CRC[0]) + "\t");
            Debug.Write(string.Format("{0:X}", CRC[1]) + "\t");
#endif
        }



        /*CRC值高阶字节 256*/
        public static readonly byte[] auchCRCHi =
        {
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
            0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01,
            0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81,
            0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
            0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01,
            0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
            0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01,
            0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
            0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
            0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01,
            0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40
            };
        /* CRC值为低阶字节256 */
        public static readonly byte[] auchCRCLo =
        {
            0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4,
            0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
            0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD,
            0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
            0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7,
            0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
            0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE,
            0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
            0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2,
            0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
            0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB,
            0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
            0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91,
            0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
            0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88,
            0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
            0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80,
            0x40
            };
        /*CRC值计算函数*/
        public static byte[] ComputeChecksumBytes(byte[] data, int data_len)
        {
            byte uchCRCHi = 0xFF; /* 高CRC字节初始化 */
            byte uchCRCLo = 0xFF; /* 低CRC 字节初始化 */
            ushort uindex; /* CRC循环中的索引 */
            for (ushort i = 0; i < data_len; i++)
            {
                uindex = (ushort)(uchCRCHi ^ data[i]);
                uchCRCHi = (byte)(uchCRCLo ^ auchCRCHi[uindex]);
                uchCRCLo = auchCRCLo[uindex];
            }
            byte[] CRC_Ret = new byte[2];
            CRC_Ret[0] = uchCRCHi;
            CRC_Ret[1] = uchCRCLo;
            return CRC_Ret;
        }

    }
  
    
}
